Costume Change
by thecanadian13
Summary: It's Halloween for Derek and Casey. Derek invites Casey to a Haunted House and she actually goes, facing more than just one fear in the process. T for minor language. One-shot.


**My Halloween treat to the Dasey Fandom Universe**

"Casey, what kind of costume is that?" Derek chuckled as he walked by Casey's room seeing her trying on costumes with Emily.

"Hush, Derek!" Emily said going to slam the door in his face.

Derek stuck his hand out in time to stop the door.

"I didn't mean it was a bad costume, I am just wondering why you'd want to dress up in that."

"I'm Belle, from Beauty and the Beast," Casey looked stunned and hurt.

"Yeah, I know princess," he replied; no pun intended. "It just looks like you grabbed that costume from the seven to eleven year old section."

Emily rolled her eyes.

"Well, I've got other costumes too," Casey said shifting her weight to one hip. "I also have Raggedy Ann, Marian Paroo from the musical The Music Man and a super hero!"

"What, are you going to be Klutzilla? Oh wait, Captain Keener. That sounds catchy."

"Why don't you just leave Derek. I like her costumes," Emily said standing up for her friend. "Even if they've been a bit dorky," she finished in a whisper.

"Fine, fine," Derek complied. "Before I do, promise me you'll stop by the haunted house at the fair tonight. It's the last night I'm working. I get to be a psychopathic doctor."

"Hah!" Casey said from the other side of the door.

"We already have plans Derek," Emily finished for Casey.

"Please," Derek said giving Emily his puppy dog look. "It'll be fun and here," he reached into his jacket pocket pulling out a mound of tickets. "I'll give you these tickets to the haunted house free of charge if you just go."

"I'm not going!" Casey yelled from her room.

"What are you scared?" Derek asked taunting her.

Emily looked back at Casey before turning back to Derek and snatching two tickets from his hand. "Fine, we'll go, but only for a little while."

"Great!" Derek said, a little too happy. "I promise, I'll scare ya really good."

With that Derek left while Casey pulled her last costume out of the bag, it's patriotic colors shimmering against the lights in her room.

* * *

Emily and Casey approached the fair grounds and took in the sight. There were literally hundreds of people of all different ages wearing outlandish costumes and walking around with orange colored popcorn and caramel apples with ghost sprinkles on top.

"This is nuts," Casey admitted as they bee-lined for the haunted house line.

The line was short, but problems soon arose.

"What do you mean these are last years tickets?" Casey asked in disbelief.

"Look, I'm sorry ma'am, but those tickets are outdated. I don't know who you got them from-"

"Derek," Casey seethed under her breath.

"But they aren't any good now," the man at the front door dressed as a zombie butler finished.

"How much to get in?" Casey asked wearily.

"$20 at the door, and $5 online before hand. Again, sorry about the mishap. Do you still want to go in?"

Casey sighed. "Well, we came all the way here…" Casey began before Emily cut in.

"Sorry Casey, I only brought a ten for food. Why don't you go through and I'll go enjoy some cheesy Halloween food," Emily said sincerely smiling.

"Alright, but if I come out shaking from terror, I'll have you to blame for not being by my side," Casey said completely serious.

"I'm sure you'll be fine Case. Just stand up to your fears."

* * *

Casey knew that was complete bullshit, but smiled at her friend before handing the dead butler her $20 bill and walking in through the front doors.

"Der-ek!" Casey screamed whipping her body around to see Derek standing on his tippy toes with his fake syringe pointing into the air.

"Casey?" He asked surprised. He looked her up and down, or as best he could in the dark haunted house. She hadn't lied at all. Not one bit. She was a super hero, but it wasn't Klutzilla or Captain Keener, it was Wonder Woman. Her hair was tucked back behind a Wonder Woman head band and her lips were a dark shade of red. She stood there pissed off, running her mouth, but all he could do was zone out. His eyes followed down her sleeveless red, gold and blue leotard to her lasso of truth. Boy, he was glad that thing was just a replica. He had just caught a glimpse of her red and white boots when Casey pushed him back and he fell over his 'operating' table.

"Derek, have you been listening to a word I've said?" Casey screamed as she walked over to the other side of the table as he lay in shock below.

Derek just gulped.

"I can't believe this! First you tell me to come to your stupid haunted house. I say no, but you almost beg me to and offer Emily and I free tickets. Then I come and it turns out, these tickets are from last year. I had to pay $20 just to get in here Derek! Emily couldn't even come in with me because she only brought $10. If I'd had known too, that your tickets were useless, I could have pre-ordered online for $5!" Casey finally breathed out a sigh as she ended her rant. She looked down at Derek waiting for at least a rebuttal, but nothing, just a blank face. "What's your problem Derek?"

Again, he said nothing, just looked up at her with hollowed eyes and a dead panned expression.

"If you are trying to stay in character Derek, I am not in the mood."

Still nothing.

"Derek?"

"I-I like your costume Case," he choked, stumbling over his words.

"What?" Casey asked confused. She really considered sending Derek to the doctor to get his hearing checked out.

"I mean it Case. I _really _ like your costume," Derek finished, finally getting to his feet.

"That's great Derek, Emily liked it too. So did Sam and Ralph I think," she said getting side tracked.

"Of course they would, any guy would," Derek said under his breath.

"But just because you like my costume," Casey started getting louder again. "Does not mean that you can get away with not answering my question!"

"Look, Case…" Derek said, holding onto her shoulders

"Don't look Case, me!" Casey said pointing a finger inches from his face.

Derek sighed before looking up with a devilish grin on his face and stepping closer to Casey before wrapping his mouth around her outstretched finger. She pulled it away quickly so it made a popping noise when it exited his mouth.

"What was that?" Casey asked surprised and puzzled. She went to rub her finger off on her clothes, but upon realizing there wasn't much to rub it off on, Casey stepped forward to use Derek's 'bloody' lab coat.

Derek didn't see it this way however. What his pre-occupied mind did see, was Casey inspecting her wet finger and stepping towards him quickly after. Without thinking, he looped his finger around her lasso and pulled her the rest of the way towards him.

"Let go of my lasso Derek," she said, not picking up on his strong body language. She never the less wrapped her finger around the material below his collar and wiped off the spit. When she went to take a step back though, she suddenly realized the presence of Derek's hands around her waist.

She looked up at his grin and that twinkle in his eyes and laughed. Once she had started laughing, she couldn't stop.

"Look, Derek…" Casey began in a tone that a parent might use to tell their child that the dog had died.

Derek didn't quite catch the inflection or the eruption of laughter that had erupted earlier as he removed his hands from her waist and grabbed her shoulders, pulling her into a kiss.

At first, instinct set in and Casey's lips moved against his. But once she had enough time to register what was happening, she pulled back, unsure of what to do next. What does one do when their step-brother kisses them? Sure, it was easy to get mad at him for pranking her or messing with her life. But what to do when he plants one on you! Casey stood stunned with a somewhat quizzical expression across her lips.

Even though Casey had pulled back, Derek couldn't keep his eyes off of those red lips. He wanted to reach up to his to see if the lipstick had rubbed off, but refrained from doing so when her hands shot up again, pushing him back down.

"What was that for Casey?" He yelled, actually landing painfully this time by a bucket filled with 'blood'.

"I think I've come to a decision," Casey said rather certain.

"That's great Case, but don't maim me in the process," Derek replied going to stand up as he rubbed the fake blood on his lab coat. "I nearly tipped over that bowl of blood."

Casey glanced quickly at the stainless steel, hospital looking bowl before reverting her attention back to her decision.

Derek looked at Casey expectantly. "So what decision did you make?"

"To not care…" Her sentence faded away as her confidence was waning.

"What are you not caring about?"

Derek's twinkle and grin had disappeared, but Casey felt adamant about not wimping out of another thing in her life. It was Halloween: a time when it was okay to be scared.

Casey pushed Derek back down again, away from the bowl of blood, as he hollered in protest. She glanced around her to make sure there were no other people walking through this part of the house before she kneeled down, straddling his hips.

Derek cocked his head to the side, that devilish grin and twinkle returning before rising up to meet Casey's hesitant lips. He pulled her down on top of him, but she wasn't kissing back. What else could she have meant when she had straddled him like that? How was he misreading this?

"I'm not caring about the consequences," Casey tried to get in between kisses.

"Fine with me," Derek replied, continuing to peck at her lips and down her neck.

"You sure?" She asked as he pulled back incredulously.

"Uh, yeah Case. Does it look like I'm down with this?" Derek smiled goofily waiting for Casey to answer.

"Yeah, I guess…"

"Ever the dramatic one," Derek sighed.

Casey rolled her eyes, before lowering herself back on top of him with one hand holding onto his shoulder and the other on the back of his head. She gave him repeated kisses on the corner of her lips as she replied between kiss, "Ever the jerk."

* * *

A group of screams broke them from their embrace as they sat up worried for a second before remembering where they were.

"Got to get to my post," Derek said to Casey as he stood up from behind the table. "This will only take a sec."

Casey peered from around the white sheet covered stainless steel table to see five girls and a couple guys looking around suspiciously at the flashing room around them.

"Care for a check-up?" Derek asked creepily holding up his syringe.

The group looked shocked when they saw him at first, probably not noticing him in the dark corner like Casey had, before shrugging it off and continuing on their way.

"That wasn't very scary Derek," Casey admitted as he crouched down beside her.

"It seemed to scare you quite a bit if I recall…" he said looking back.

"That's because you popped up right behind me Derek!" Casey said playfully punching his shoulder. "And if I do remember, you also looked put out when you saw me as well."

Derek blushed slightly, if that was a manly enough thing for him to do. "I wasn't scared Case…"

"I know," she said smiling evilly. "You just_ really _liked my costume."


End file.
